I am a fan of utilizing equity in existing real estate owned to build the rental portfolio though at the beginning, rather than just relying on money saved alone.  

Open to an existing home with a large lot/acreage.

Demolish The Home and Build New: You can demolish the existing house and build new.

We have never taken money out of the rental business, it either goes towards buying more properties, improving existing ones or paying off loans.

However, seasonality still exists and the summer is low season.

How are you comparing the cost of a new build to one with an existing duplex?

To get this amount through a cash-out refinance at 80% LTV, the home value must be at least $453,800 after one year.Based on your report your ARV right after reno is $425,000Add a 8% home appreciation for one year $34,000Estimated Home Value After 1 Year:$459,000Assuming a refinance after 12 months with a property value of $459,000: New Home Value (Post-Appreciation): $459,000 New Mortgage Amount (80% LTV): $367,200 Existing Debt Balance after 12 months: -$360,000 (because you have been paying interest only) Assuming Bank fees on New Mortgage: - $200 Cash Pulled Out: $7,001, allowing you to recover to pay only 7k on your initial investment of $29,790, leaving $ $22,789 in the deal.Many new investors mistakenly believe the BRRRR strategy ends after the cash-out.

Looking to tap into it without doing a cash out refi to replace the existing rates with current rates.

And yes, you can buy existing stuff at a discount from new construction for sure. 

Regarding renting your existing home, you have to look at it as a business.